Adjustable cylinder head holder

ABSTRACT

Apparatus for reworking the valve guides of a cylinder head is disclosed. The apparatus includes an adjustable cylinder head holder including a base, a pedestal and a heat support subassembly permitting positioning of the head rotationally about its longitudinal axis as well as pivotally about a transverse axis. A pair of such cylinder head supports are supported on an elongated member for transverse adjustable movement. The elongated member is supported on a bed plate beneath the spindle of a drill press. Valve guide reworking tools secured to the spindle by a U-joint are aligned with and guided through the valve guides by a valve guide boring fixture securable to the cylinder head.

This is a division of Ser. No. 094,453, filed Nov. 15, 1979, and nowabandoned.

BACKGROUND OF THE INVENTION

The present invention relates to apparatus for reworking the valveguides of an internal combustion engine including apparatus forsupporting and positioning a cylinder head during valve guide reworkingoperations.

The valve guides of an internal combustion engine become excessivelyworn during extended use. The tolerances between the valve stem and thevalve guide must be maintained fairly close in order for the engine tooperate efficiently. Heretofore, a fairly wide variety of tools,machines and supports have been proposed for use in repairing the valveguides of internal combustion engine cylinder heads. A typical method bywhich the valve guides are reworked includes the step of boring the wornvalve guides, inserting a tubular insert and then reaming the insert torequired tolerances. Such a method is taught, for example, in commonlyowned U.S. Pat. No. 3,828,756 entitled Method and Apparatus forRebuilding Valve Guides and issued on Aug. 13, 1974 to Kammeraad et al.

During the rebuilding and reworking of the valve guides, the cylinderhead must be supported and positioned to permit the performance of theboring and reaming operations. Fairly large, complex and expensivemachines have been developed for such reworking operations. Thesemachines are large and relatively immovable and require the precisemounting of a cylinder head at a proper angle in order to produce theproper reworking alignment. Such machines typically include a heavyduty, geared head press, a custom table and an adjustable head cradle.The internal combustion engine cylinder head is mounted in the cradlewhich is adjustable to permit proper positioning of the head relative tothe head press. Rotational and angular positioning of the cylinder headis necessary since many cylinder heads include canted ornonperpendicular valve guides.

Smaller tools mountable directly on the cylinder head and which permitthe reworking of the valve guides with hand-operated tools have alsobeen proposed. An example of one such apparatus may be found in commonlyowned U.S. Pat. No. 3,764,204, entitled Valve Guide Boring Fixture andissued on Oct. 9, 1973 to Kammeraad. This patent discloses a generallyU-shaped boring fixture mountable on a cylinder head at the valve guide.The fixture includes a guide arm securable to the cylinder head at thevalve seat and a guide arm engageable with the cylinder head at thevalve spring seat. The first guide arm includes an adjustably mountedaxial bore adapted to guide various valve guide reworking tools. Whenusing a valve guide boring fixture of this type, the cylinder head issupported on head support stands in order to provide sufficientclearance above and below the head to mount the boring fixture.

Different forms of cylinder head stands or holders have heretofore beenproposed. Examples may be found in U.S. Pat. No. 3,261,599, entitledCylinder Head Holder and issued on July 19, 1966 to Holmen and U.S. Pat.No. 3,048,387, entitled Holding Fixture for Cylinder Heads and issued onAug. 7, 1962 to Waggoner. The cylinder head holder disclosed in theHolmen patent includes a base and a vertically extending tapered rod.The rod is adapted to be inserted through a bolt hole of a cylinderhead. A pair of such holders are positioned at each end of the cylinderhead to support the head in a single, nonadjustable position. The headmay, however, be mounted on the holders with either side up.

The stand disclosed in the Waggoner patent includes a base plate and acylindrical post through which extends a rotatable and transverselypositionable rod. The rod supports on one end an elongated bar securableto the cylinder head and a segmental plate connected to the bar. Theplate structure and rod permit the cylinder head to be rotated about anaxis perpendicular to the top and bottom of the cylinder head and alsoswinging adjustment of the bar and head relative to the post. The standdisclosed in the Waggoner patent, therefore, permits some angular,rotational and vertical adjustment of the head relative to a bench orother support surface. Adjustment of the head is not, however,accomplished in a single vertical plane.

Heretofore, apparatus has not been available for adjustably supporting acylinder head in a plurality of longitudinal and transverse axialpositions within the same plane. Further, apparatus has not beenavailable which would permit the reworking of the valve guides in aconventional drill press.

SUMMARY OF THE INVENTION

In accordance with the present invention, apparatus is provided forsupporting a cylinder head during valve guide reworking which permitsrotational adjustment of the cylinder head about its longitudinal axisas well as transverse axial adjustment so that one end of the cylinderhead may be raised above the other end. Further, apparatus is providedfor the reworking of the valve guide with a conventional drill press.Essentially, the cylinder head support apparatus includes a basestructure, a pedestal and head support means mounted on the pedestal forsupporting a cylinder head and permitting positioning of the head abouta longitudinal and a transverse axis. Further, provision is made forvertical adjustment of the head support means relative to the pedestal.

In further aspects of the invention, apparatus is provided forsupporting a pair of cylinder head stands and positioning the stands anda cylinder head beneath the spindle of a drill press. A valve guideboring fixture can then be positioned on the cylinder head and reworkingaccomplished by reworking tools rotated by the drill press through auniversal joint. The cylinder head stands are laterally movable on thepositioning means to permit accurate alignment of a head relative to thedrill press spindle.

The cylinder head stands in accordance with the present inventionsupport a cylinder head permitting the head to be rotated about itslongitudinal axis through an angle of 360°. This easily permits the headto be turned over after it is mounted on the stand. The transverseangular adjustment feature of the stand permits one end of the cylinderhead to be supported above its other end. This permits accuratepositioning of the head for ease of working of canted ornonperpendicular valve guides. The stands and positioning means permitreworking of the cylinder head employing a conventional drill press.This has not, heretofore, been readily accomplished.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary, perspective view of a cylinder head mounted ona holding apparatus and positioned beneath the head of a drill press inaccordance with the present invention;

FIG. 2 is a front, elevational view of a cylinder head stand inaccordance with the present invention;

FIG. 3 is a side, elevational view of the cylinder head stand;

FIG. 4 is a top plan view of a positioning subassembly incorporated inthe present invention; and

FIG. 5 is a top plan view of an alternative embodiment of thepositioning subassembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The preferred embodiment of the valve guide reworking apparatus andcylinder head support apparatus in accordance with the present inventionis illustrated in FIGS. 1 and 4 and generally designated 10. Apparatus10 includes a pair of cylinder head stands or head support means 12mounted on a positioning subassembly 14 which in turn is positioned on abed 16 of a drill press 18. The drill press 18 is conventional in natureand includes a vertically oriented post 20 upon which is positioned ahead subassembly 22. The head subassembly includes a suitable electricmotor 24 for driving a spindle 26. In the preferred embodiment of thepresent invention, a valve guide reworking tool 28 is rotated by thespindle 26 through a U-joint 30.

FIG. 1 illustrates a cylinder head 32 supported in proper angularrelationship and positioned beneath the spindle 26 on stands 12. Securedto the cylinder head is a valve guide boring fixture generallydesignated 34. Valve guide boring fixture 34 is of the type illustratedand described in commonly owned U.S. Pat. No. 3,764,204, entitled ValveGuide Boring Fixture and issued on Oct. 9, 1973 to John H. Kammeraad,the disclosure of which is hereby incorporated by reference. The valveguide boring fixture 34 includes a first guide arm 36 and a second guidearm 38. The first guide arm 36 supports a valve seat engaging means (notshown) which includes a ball swivel guide, a boring guide or drillbushing and a valve seat adaptor. The second guide arm 38 supports aspring seat adaptor (not shown). Fixture 34 may be accurately alignedwith the valve guide to be bored and reworked. The fixture providesaccurate guidance of a reworking tool 28 preventing the tool fromstraying from a properly aligned axis through the valve guide during thereworking operation.

The adjustable head holder or stand is best seen in FIGS. 2 and 3. Asshown therein, the stand includes a base 40, a pedestal 42 and anadjustable head support means 44. The pedestal 42 is a hollow, tubularcylindrical item and extends vertically and generally centrally from anupper surface 46 of base 40. As seen in FIG. 2, base 40 defines atransverse slot 48 therethrough. Pedestal 42 may be secured within aboss formed integral with the upper surface 46 of base 40 or thepedestal may be welded to the upper surface of the base.

The head support means 44 permits rotational adjustment of a cylinderhead about its longitudinal axis 47 (FIGS. 3 and 5) as well as angularadjustment of the head about a transverse axis 76 (FIGS. 2 and 3). Theaxes are mutually perpendicular and lie in parallel, horizontal planes.Means 44 includes a post 50 which is threaded along its length 52. Post50 is dimensioned to be telescopingly received within pedestal 42.

Vertical positioning of post 50 is accomplished by a vertical adjustmentnut 54 having a threaded through bore 56. Nut 54 rests on the upper end58 of pedestal 42 and threadably engages post 50. As a result, rotationof nut 54 shifts post 50 vertically with respect to pedestal 42 and base40.

Secured to top 60 of post 50 is a knuckle joint 62. Knuckle joint 62includes a first bifurcated or yoke member 64 having a base 66 welded,formed integral with, or otherwise suitably secured to the post and apair of opposed, spaced, parallel legs 68, 70. A pivot piece or pivotingmember 72 of the joint is disposed between legs 68, 70 and a pivot pin74 extends through the legs and the pivot member. As a result, member 72is pivotal about an axis 76 lying within a horizontal plane which isparallel with the top surface 46 of base 40.

Supported on pivot member 72 is a rotational adjustment and cylinderhead engaging means 80. Means 80 includes an elongated, generally flatplate 82 formed with suitable slots 84 extending between the top andbottom surfaces thereof. Plate 82 is adapted to be secured to a cylinderhead by suitable bolts passing through the slots 84 and through thecylinder head bolt holes. Plate 82 is welded or otherwise suitablysecured to an end face 86 of a generally cylindrical, plug-like member88. Member 88 is held by a band-type, circular clamp 90. Clamp 90 iswelded or otherwise suitably secured to pivot piece 72. Clamp 90includes a circular member 92 which encircles member 88 and has opposedends 94, 96. In the embodiment illustrated in FIG. 2, ends 94, 96 havealigned bores 98, 100. Bore 100 is internally threaded at 102. A bolttype lock 104 extends through bore 98 and threadably engages bore 100.An extension 106 is secured to bolt 104 and includes a transverse bore108 through which a handle 110 extends. Rotation of handle 110 permitsthe opposed ends 94, 96 of the clamp to be moved towards and away fromeach other. When the clamp is opened up, plate 82 may be positioned byrotation of member 88 within clamp portion 92 about the center axis ofmember 88. Handle 110 may then be rotated to close the ends towards eachother to thereby clamp and position the plate 82. The band clamp andcylindrical member arrangement permit the plate and hence a cylinderhead to be rotated about its longitudinal axis through an angle of 360°.

Pedestal 42 is formed with an elongated, vertical slot 112. Post 50adjacent its lower end is formed with a through bore 113 which isthreaded along its length. A threaded rod 114 extends through slot 112and threadably engages the bore 113. Positioned on rod 114 and engagingthe surface of pedestal 42 is a washer 115 having a saddleshaped surface116 which engages the outer surface of the pedestal. A handle 117 isnonrotatably secured to threaded rod 114. Threaded rod 114 permits post50 to be locked in position. Once the vertical position of the post isset, the operator merely turns the knob 117 which presses the washer 115into frictional engagement with the outer surface of the pedestal.

The cylinder head may be positioned with either face up and/or with theface positioned at any angle with respect to a horizontal plane.Further, the knuckle joint permits the cylinder head to be tilted orpivoted about a transverse axis at its ends. The axis of rotation ofmember 88 is perpendicular to the pivot axis of the knuckle joint. Thecylinder head, as seen in FIGS. 1 and 4, may be supported by the stands12 and positioned in multiple angularly related orientations all ofwhich lie in the same vertical plane. Post 50 of one stand may be raisedabove post 50 of the other stand. Knuckle joints 62 accommodate theangular adjustment. The stands, therefore, readily and accuratelyposition the cylinder head so that boring operations on canted valveguides are easily and readily accomplished.

As seen in FIGS. 1 and 4, the cylinder head stands are supported on apositioning means 14. Positioning means 14 includes a bed plate 120which is positioned on the base or bed 16 of drill press 18. Thepositioning apparatus includes an elongated member or link 122 which ismovable towards and away from lateral edge 124 of plate 120 in aparallel manner. Links 126, 128 insure that member 122 is alwaysmaintained parallel with lateral edge 124. Each link 126, 128 is pivotedat an end 130 to bed plate 120. The opposite ends 132 of the links arepivoted at opposed ends 134, 136, respectively, of the elongated link122. As best seen in FIGS. 2 and 4, base 40 of each stand 12 is slidablymounted on elongated member 22 with member 22 being received within slot48. Base 40 of stand 12 and link 122 define a tongue and groove typeslide track. As a result, the stands may be slidably positioned onmember 122 to permit lateral positioning of the cylinder head relativeto the drill press spindle.

Positioning means 14 also includes a pair of lock means 140 at each link126, 128. Each lock means 140 includes a knurled knob 142. Rotation ofknob 142 causes a threaded member to engage pivot pins 144 whichpivotally mount links 126, 128. This locks the links in position afterthe head has been moved under the drill press head.

Also, as seen in FIG. 4, bed plate 120 preferably supports a pluralityof leveling screws 148 at each corner thereof. Screws 148 are used toinsure that plate 120 is supported in a level position on drill pressbase 16.

OPERATION

In operation, a cylinder head is supported at each end by stand 12. Oneend of the cylinder head may be raised above the other end merely byrotation of adjustment nut 54 which raises the post 50 relative topedestal 42. The posts may then be locked by rotation of handle 117. Thetransverse angular orientation of the cylinder is accommodated byknuckle joints 62. Rotational adjustment of the cylinder head isaccomplished by rotation of plates 82 within band clamps 90. Thecylinder head is attached to the support plates 82 by bolts passingthrough slots 84 and through the cylinder head bolt holes.

Once the cylinder head is supported on stands 12 which rest uponelongated member or link 122 of positioning means 14, link 122 may bepushed towards lateral edge 124 of bed plate 120 in order to move thecylinder head into position under spindle 26 of the drill press 18.Valve guide boring fixture 34 is secured to the cylinder head at thevalve guide to be reworked. The fixture is secured in accordance withthe description contained in U.S. Pat. No. 3,764,204. The angularorientation of the cylinder head may then be set and the stands locked.When the front-to-back alignment is obtained through positioning means14, the linkages are locked in position by lock means 140. The cylinderhead and stands 112 may then be slidably moved along member 122 untilthe valve guide reworking tool 28 is properly aligned with the boringfixture 34. U-joint 30 reduces the required accuracy of the alignment.The boring guide fixture 34 may be slightly misaligned from the verticalor longitudinal axis of the spindle and proper operation of the tool 28will still be obtained through the U-joint 30. This reduces the set-uptime and simplifies use of the apparatus.

Once the cylinder head is in position beneath the spindle of the drillpress, the press may be operated to feed the tool through the fixturethereby reworking the valve guide. Multiple angular positioning of thecylinder head is obtained in order to properly align a canted valveguide bore with the reworking tool and the spindle of the drill press.Once the reworking operation has been completed on the first valveguide, subsequent reworking is obtained merely by shifting the cylinderhead and stands laterally along member 128 until the next valve guide isin position beneath the spindle and reworking tool.

ALTERNATIVE EMBODIMENT

An alternative embodiment of the positioning means is illustrated inFIG. 5 and generally designated 14'. Means 14' includes an elongated bar152 having ends 154 and 156. End 154 is pivotally secured to bed plate120 by a pin 158 at a transverse edge 160 of plate 120. A cylinder head32 is supported on stands 12 as in the previous embodiment. Slots 48 ofeach stand 12 mounts the stands and the head to bar 152. Bar 152 isadjustable towards and away from lateral edge 124 of plate 120 by anadjustment means 164. Means 164 includes a threaded member 166threadably engaging a threaded boss 168 on end 156 of bar 152. Member166 is supported for rotation by a bearing assembly 170 secured to plate120. A knurled knob 172 is nonrotatably secured to member 166.

As should now be readily apparent, once cylinder head 32 is secured tostands 12 on bar 152, the head may be accurately positioned relative tothe reworking tools, by sliding the stands along bar 152 and pivoting ofbar 152 towards or away from edge 142 through means 164. Reworking ofthe valve guides is then accomplished as described above.

The apparatus in accordance with the present invention permits efficientand relatively inexpensive reworking of valve guides employing powertools which have heretofore not been usable for valve guide reworkingoperations. The apparatus is significantly less expensive and lesscomplicated than the large head machines which have been employed forreworking valve guides. Stands 12 permit easy and ready adjustment ofthe cylinder head to permit it and the boring fixture to be accuratelypositioned relative to a conventional drill press. Positioning means 14permits the front-to-back relationship to be set once during theoperation. Also, the linkage structure permits the stands and cylinderhead to be moved out from beneath the spindle for removal and mountingof the cylinder head and boring guide fixture. Stands 12 permit thecylinder head to be rotated or turned over so that reworking operationsmay be performed from either side of the cylinder head. This simplifiespreparation of the cylinder head for valve guide reworking and alsosimplifies replacement of valves and springs. The stands and positioningmeans are easily and relatively inexpensively manufactured employingconventional materials and methods.

In view of the foregoing description, those of ordinary skill in the artwill undoubtedly envision various modifications to the present inventionwhich would not depart from the inventive concepts disclosed. Forexample, band clamp 20 could employ an overcenter cam lock as opposed tothe bolt lock illustrated. The overcenter cam lock would, in fact, bepreferred due to its increased simplicity and ease of operation. Also,positioning means other than that shown could be used. The primeconsideration is the accurate front-to-back alignment of the cylinderhead relative to the drill press. It is expressly intended, therefore,that the above description should be considered as only that of thepreferred embodiment. The true spirit and scope of the present inventionmay be determined by reference to the appended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. An apparatus forsupporting a cylinder head in position beneath a drill press duringboring of the head valve guides, the drill press including a verticalpost and a head, said apparatus comprising:a base plate positionablebelow the drill press head; a pair of transversely spaced, opposedcylinder head stand means for supporting a cylinder head, each of saidstand means including means for permitting rotational and means forpermitting angular positional adjustment of the cylinder head in asingle vertical plane about two perpendicularly related axes; andpositioning means on said plate and supporting said pair of stand meansfor permitting selective positioning of said pair of stand means tovalve guide boring positions beneath the drill press head, said pair ofstand means being laterally shiftable on said base plate by saidpositioning means to permit alignment of each valve guide of thecylinder head with the drill press.
 2. An apparatus as defined by claim1 wherein said positioning means comprises:an elongated member uponwhich said pair of stand means are supported, each of said stand meansincluding a base member defining a transverse slot through which saidelongated member extends, said member thereby defining a track alongwhich each of said stand means may be slidably positioned.
 3. Anapparatus as defined by claim 1 wherein each of said stand meanscomprises:a base member; a pedestal extending generally vertically fromsaid base member; and a head support means on said pedestal for engagingand supporting the cylinder head, said head support means includingmeans for permitting rotational and angular positioning of the headabout a longitudinal axis of the head and a transverse axis of the head,respectively.
 4. An apparatus for supporting a cylinder head in positionbeneath a drill press during boring of the head valve guides, the drillpress including a vertical post and a head, said apparatus comprising:abase plate positionable below the drill press head; a pair oftransversely spaced, opposed cylinder head stand means for supporting acylinder head, each of said stand means including means for permittingrotational and means for permitting angular positional adjustment of thecylinder head in a single vertical plane; and positioning means on saidplate and supporting said pair of stand means for permitting selectivepositioning of said pair of stand means to valve guide boring positionsbeneath the drill press head, said pair of stand means being laterallyshiftable on said base plate to permit alignment of each valve guide ofthe cylinder head with the drill press, each of said stand meanscomprising: a base member; a pedestal extending generally verticallyfrom said base member; and a head support means on said pedestal forengaging and supporting the cylinder head, said head support meansincluding means for permitting rotational and angular positioning of thehead about a longitudinal axis of the head and a transverse axis of thehead, respectively, and wherein said head support means comprises: apost telescopingly disposed within said pedestal and supporting saidhead support means; and vertical adjustment means on said pedestal foradjusting the vertical position of said post relative to said pedestal.5. An apparatus as defined by claim 4 wherein said head support meansfurther comprises:a knuckle joint on top of said post; and a headsupport plate mounted on said knuckle joint whereby the post of one ofsaid stand means may be raised higher than the post of the other ofstand means so that the cylinder head may be supported below said drillpress head with one end higher than the other.
 6. An apparatus asdefined by claim 4 wherein said head support means further comprises:ahead support plate having a plurality of slots therethrough; acylindrical member having an end face to which said plate is secured;and a band clamp encircling said cylindrical member for adjustablypositioning said cylindrical member through an angle of 360°, said bandclamp being supported by said post.
 7. An apparatus as defined by claim6 wherein said head support means further comprises:a knuckle jointjoining said band clamp to said post, said knuckle joint permittingpivotal movement of said head support plate about an axis in a planeparallel to the plane of the axis of rotation of said cylindrical memberand perpendicular thereto.
 8. An apparatus as defined by claim 7 whereinsaid positioning means comprises:an elongated member upon which saidpair of stand means are supported; and a pair of parallel links, eachlink having an end pivoted to the base plate and an end pivoted to saidelongated member, whereby said links restrict said elongated member toparallel movement towards and away from a lateral edge of the baseplate.
 9. An apparatus as defined by claim 7 wherein said positioningmeans comprises:an elongated member upon which said pair of stand meansare supported, said elongated member having an end pivoted to said baseplate; and adjustment means on said base plate for moving another end ofsaid elongated member towards and away from a lateral edge of said baseplate.